Split 6 portobella mushrooms caps into 12 thin rounds. Toss together 1 1/4 cup shredded muenster cheese, 2/3 cup plain breadcrumbs, 2 tablespoons chopped parsley, 1 minced garlic clove, and salt and pepper, to taste. Layer the portobella rounds and cheese mixture in a baking dish, making 3 layers of each. Drizzle with 3 tablespoons water, cover with foil and bake at 400 degrees, 35 minutes. Uncover and bake 8 more minutes.